It's colder yet at many other interior Alaska stations, including -50 °F in Eagle and -58 °F in Chicken.
The chart below shows the annual number of days reaching -40 °F (total column height) and -50 °F (red columns) in Fairbanks since 1930. The long-term decline is very noticeable, especially for -50 °F days which have become rare. However, there was tremendous year-to-year variability prior to about 1975; some winters had few or no extreme cold days, while others had many. Superficially, it appears that variability has decreased, but this could be an artifact of sampling a smaller portion of the climate distribution in recent decades.
Webcam photos from around Fairbanks show the clear skies and shallow ice fog that are typical in association with deep cold.